Add thumbnail mode option

i18n/en/cosmic_files.ftl

@@ -297,6 +297,12 @@ type-to-search = Type to Search
 type-to-search-recursive = Searches the current folder and all subfolders
 type-to-search-enter-path = Enters the path to the directory or file
 
+### Thumbnail mode
+thumbnail-mode = Thumbnails
+thumbnail-mode-local = Show for local files only
+thumbnail-mode-all = Show for local and network files
+thumbnail-mode-never = Never show
+
 # Context menu
 add-to-sidebar = Add to sidebar
 compress = Compress

src/app.rs

@@ -72,7 +72,7 @@ use crate::{
     clipboard::{ClipboardCopy, ClipboardKind, ClipboardPaste},
     config::{
         AppTheme, Config, DesktopConfig, Favorite, IconSizes, TIME_CONFIG_ID, TabConfig,
-        TimeConfig, TypeToSearch,
+        ThumbnailMode, TimeConfig, TypeToSearch,
     },
     dialog::{Dialog, DialogKind, DialogMessage, DialogResult},
     fl, home_dir,
@@ -404,6 +404,7 @@ pub enum Message {
     SearchClear,
     SearchInput(String),
     SetShowDetails(bool),
+    SetThumbnailMode(ThumbnailMode),
     SetTypeToSearch(TypeToSearch),
     SystemThemeModeChange,
     Size(window::Id, Size),
@@ -1418,11 +1419,17 @@ impl App {
         let tabs: Box<[_]> = self.tab_model.iter().collect();
         // Update main conf and each tab with the new config
         let commands = std::iter::once(cosmic::command::set_theme(self.config.app_theme.theme()))
-            .chain(tabs.into_iter().map(|entity| {
-                self.update(Message::TabMessage(
-                    Some(entity),
-                    tab::Message::Config(self.config.tab),
-                ))
+            .chain(tabs.into_iter().flat_map(|entity| {
+                [
+                    self.update(Message::TabMessage(
+                        Some(entity),
+                        tab::Message::Config(self.config.tab),
+                    )),
+                    self.update(Message::TabMessage(
+                        Some(entity),
+                        tab::Message::ThumbConfig(self.config.thumb_cfg),
+                    )),
+                ]
             }));
         Task::batch(commands)
     }
@@ -1952,6 +1959,36 @@ impl App {
                     Message::SetTypeToSearch,
                 ))
                 .into(),
+            widget::settings::section()
+                .title(fl!("thumbnail-mode"))
+                .add(widget::settings::item_row(vec![
+                    widget::radio(
+                        widget::text::body(fl!("thumbnail-mode-local")),
+                        ThumbnailMode::Local,
+                        Some(self.config.thumb_cfg.thumbnail_mode),
+                        Message::SetThumbnailMode,
+                    )
+                    .into(),
+                ]))
+                .add(widget::settings::item_row(vec![
+                    widget::radio(
+                        widget::text::body(fl!("thumbnail-mode-all")),
+                        ThumbnailMode::All,
+                        Some(self.config.thumb_cfg.thumbnail_mode),
+                        Message::SetThumbnailMode,
+                    )
+                    .into(),
+                ]))
+                .add(widget::settings::item_row(vec![
+                    widget::radio(
+                        widget::text::body(fl!("thumbnail-mode-never")),
+                        ThumbnailMode::Never,
+                        Some(self.config.thumb_cfg.thumbnail_mode),
+                        Message::SetThumbnailMode,
+                    )
+                    .into(),
+                ]))
+                .into(),
             widget::settings::section()
                 .title(fl!("other"))
                 .add({
@@ -3728,6 +3765,12 @@ impl Application for App {
                 config_set!(show_details, show_details);
                 return self.update_config();
             }
+            Message::SetThumbnailMode(thumbnail_mode) => {
+                let mut new_thumb_cfg = self.config.thumb_cfg.clone();
+                new_thumb_cfg.thumbnail_mode = thumbnail_mode;
+                config_set!(thumb_cfg, new_thumb_cfg);
+                return self.update_config();
+            }
             Message::SetTypeToSearch(type_to_search) => {
                 config_set!(type_to_search, type_to_search);
                 return self.update_config();

src/config.rs

@@ -102,6 +102,23 @@ impl Favorite {
     }
 }
 
+/// Stores configuration for when thumbnails should be generated.
+#[derive(Clone, Copy, Debug, Deserialize, Hash, Eq, PartialEq, Serialize)]
+pub enum ThumbnailMode {
+    /// Generate thumbnails for local images only
+    Local,
+    /// Generate thumbnails for local and remote images
+    All,
+    /// Never generate thumbnails
+    Never,
+}
+
+impl Default for ThumbnailMode {
+    fn default() -> Self {
+        ThumbnailMode::Local
+    }
+}
+
 #[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
 pub enum TypeToSearch {
     Recursive,
@@ -294,6 +311,7 @@ pub struct ThumbCfg {
     pub jobs: NonZeroU16,
     pub max_mem_mb: NonZeroU16,
     pub max_size_mb: NonZeroU16,
+    pub thumbnail_mode: ThumbnailMode,
 }
 
 impl Default for ThumbCfg {
@@ -302,6 +320,7 @@ impl Default for ThumbCfg {
             jobs: 4.try_into().unwrap(),
             max_mem_mb: 2000.try_into().unwrap(),
             max_size_mb: 64.try_into().unwrap(),
+            thumbnail_mode: ThumbnailMode::default(),
         }
     }
 }

src/mounter/gvfs.rs

@@ -11,7 +11,7 @@ use super::{Mounter, MounterAuth, MounterItem, MounterItems, MounterMessage};
 use crate::{
     config::IconSizes,
     err_str,
-    tab::{self, DirSize, ItemMetadata, ItemThumbnail, Location},
+    tab::{self, DirSize, ItemLocation, ItemMetadata, Location},
 };
 
 const TARGET_URI_ATTRIBUTE: &str = "standard::target-uri";
@@ -166,7 +166,8 @@ fn network_scan(uri: &str, sizes: IconSizes) -> Result<Vec<tab::Item>, String> {
             icon_handle_grid,
             icon_handle_list,
             icon_handle_list_condensed,
-            thumbnail_opt: Some(ItemThumbnail::NotImage),
+            thumbnail_opt: None,
+            item_location: ItemLocation::Remote,
             button_id: widget::Id::unique(),
             pos_opt: Cell::new(None),
             rect_opt: Cell::new(None),

src/tab.rs

@@ -76,7 +76,10 @@ use crate::{
     FxOrderMap,
     app::{Action, PreviewItem, PreviewKind},
     clipboard::{ClipboardCopy, ClipboardKind, ClipboardPaste},
-    config::{DesktopConfig, ICON_SCALE_MAX, ICON_SIZE_GRID, IconSizes, TabConfig, ThumbCfg},
+    config::{
+        DesktopConfig, ICON_SCALE_MAX, ICON_SIZE_GRID, IconSizes, TabConfig, ThumbCfg,
+        ThumbnailMode,
+    },
     dialog::DialogKind,
     fl,
     localize::{LANGUAGE_SORTER, LOCALE},
@@ -679,10 +682,11 @@ pub fn item_from_gvfs_info(path: PathBuf, file_info: gio::FileInfo, sizes: IconS
         icon_handle_grid,
         icon_handle_list,
         icon_handle_list_condensed,
-        thumbnail_opt: if remote {
-            Some(ItemThumbnail::NotImage)
+        thumbnail_opt: None,
+        item_location: if remote {
+            ItemLocation::Remote
         } else {
-            None
+            ItemLocation::Local
         },
         button_id: widget::Id::unique(),
         pos_opt: Cell::new(None),
@@ -824,7 +828,12 @@ pub fn item_from_entry(
         icon_handle_grid,
         icon_handle_list,
         icon_handle_list_condensed,
-        thumbnail_opt: remote.then_some(ItemThumbnail::NotImage),
+        thumbnail_opt: None,
+        item_location: if remote {
+            ItemLocation::Remote
+        } else {
+            ItemLocation::Local
+        },
         button_id: widget::Id::unique(),
         pos_opt: Cell::new(None),
         rect_opt: Cell::new(None),
@@ -1045,7 +1054,7 @@ pub fn scan_search<F: Fn(&Path, &str, Metadata) -> bool + Sync>(
         not(target_os = "android")
     )
 )))]
-pub fn scan_trash(_sizes: IconSizes) -> Vec<Item> {
+pub fn scan_trash(_sizes: IconSizes, _thumbnail_mode: ThumbnailMode) -> Vec<Item> {
     log::warn!("viewing trash not supported on this platform");
     Vec::new()
 }
@@ -1112,7 +1121,8 @@ pub fn scan_trash(sizes: IconSizes) -> Vec<Item> {
                 icon_handle_grid,
                 icon_handle_list,
                 icon_handle_list_condensed,
-                thumbnail_opt: Some(ItemThumbnail::NotImage),
+                thumbnail_opt: None,
+                item_location: ItemLocation::Trash,
                 button_id: widget::Id::unique(),
                 pos_opt: Cell::new(None),
                 rect_opt: Cell::new(None),
@@ -1281,7 +1291,8 @@ pub fn scan_desktop(
             icon_handle_grid,
             icon_handle_list,
             icon_handle_list_condensed,
-            thumbnail_opt: Some(ItemThumbnail::NotImage),
+            thumbnail_opt: None,
+            item_location: ItemLocation::Trash,
             button_id: widget::Id::unique(),
             pos_opt: Cell::new(None),
             rect_opt: Cell::new(None),
@@ -1533,6 +1544,7 @@ pub enum Message {
     DoubleClick(Option<usize>),
     ClickRelease(Option<usize>),
     Config(TabConfig),
+    ThumbConfig(ThumbCfg),
     ContextAction(Action),
     ContextMenu(Option<Point>, Option<window::Id>),
     LocationContextMenuPoint(Option<Point>),
@@ -1616,6 +1628,17 @@ pub enum DirSize {
     Error(String),
 }
 
+/// Identifies the location category of an item for the purposes of generating a thumbnail.
+#[derive(Clone, Debug)]
+pub enum ItemLocation {
+    /// Item is on the local filesystem, but not in the trash
+    Local,
+    /// Item is on a remote filesystem
+    Remote,
+    /// Item is in the trash
+    Trash,
+}
+
 #[derive(Clone, Debug)]
 pub enum ItemMetadata {
     Path {
@@ -1680,11 +1703,26 @@ impl ItemMetadata {
     }
 }
 
+/// Represents different types of thumbnails that can be generated for file system items.
+///
+/// Thumbnails are generated lazily and only for visible items to optimize performance.
+/// The thumbnail generation respects memory limits and file size constraints configured
+/// by the user.
 #[derive(Debug)]
 pub enum ItemThumbnail {
+    /// Indicates that the item cannot be thumbnailed or is not an image/previewable file.
+    /// This is used as the default fallback for non-previewable content.
     NotImage,
+
+    /// A raster image thumbnail containing an image handle and optional original dimensions.
+    /// The dimensions tuple represents (width, height) of the original image if available.
     Image(widget::image::Handle, Option<(u32, u32)>),
+
+    /// An SVG thumbnail containing a vector graphics handle for scalable images.
     Svg(widget::svg::Handle),
+
+    /// A text preview containing the file's text content for display in a text editor widget.
+    /// Note: Currently disabled in the UI due to performance issues with text shaping.
     Text(widget::text_editor::Content),
 }
 
@@ -2008,7 +2046,17 @@ pub struct Item {
     pub icon_handle_grid: widget::icon::Handle,
     pub icon_handle_list: widget::icon::Handle,
     pub icon_handle_list_condensed: widget::icon::Handle,
+    /// Optional thumbnail representation for this item.
+    ///
+    /// - `None`: No thumbnail has been generated yet (lazy loading)
+    /// - `Some(ItemThumbnail::NotImage)`: Item is not previewable
+    /// - `Some(ItemThumbnail::Image/Svg/Text)`: Generated thumbnail for preview
+    ///
+    /// Thumbnails are generated asynchronously only for visible items through a subscription
+    /// system to optimize performance and memory usage.
     pub thumbnail_opt: Option<ItemThumbnail>,
+    /// Describes the item location for the purposes of thumbnail generation
+    pub item_location: ItemLocation,
     pub button_id: widget::Id,
     pub pos_opt: Cell<Option<(usize, usize)>>,
     pub rect_opt: Cell<Option<Rectangle>>,
@@ -2341,6 +2389,17 @@ impl Item {
         row = row.push(column);
         row.into()
     }
+
+    /// Determines if a thumbnail may be generated, based on the thumbnail mode and item location.
+    pub fn allow_generate_thumbnail(&self, thumbnail_mode: &ThumbnailMode) -> bool {
+        match (thumbnail_mode, &self.item_location) {
+            (ThumbnailMode::Local, ItemLocation::Local) => true,
+            (ThumbnailMode::Local, ItemLocation::Remote) => false,
+            (ThumbnailMode::All, _) => true,
+            (_, ItemLocation::Trash) => false,
+            (ThumbnailMode::Never, _) => false,
+        }
+    }
 }
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Deserialize, Serialize)]
@@ -3128,6 +3187,27 @@ impl Tab {
                     }
                 }
             }
+            Message::ThumbConfig(thumb_config) => {
+                let thumbnail_mode_changed =
+                    self.thumb_config.thumbnail_mode != thumb_config.thumbnail_mode;
+                self.thumb_config = thumb_config;
+                if thumbnail_mode_changed {
+                    // Reloads the tab if thumbnail mode was changed, so that when thumbnails are
+                    // disabled the tab immediately updates to hide them.
+                    let selected_paths = self
+                        .selected_locations()
+                        .into_iter()
+                        .filter_map(Location::into_path_opt)
+                        .collect();
+                    let location = self.location.clone();
+                    self.change_location(&location, None);
+                    commands.push(Command::ChangeLocation(
+                        self.title(),
+                        location,
+                        Some(selected_paths),
+                    ));
+                }
+            }
             Message::ContextAction(action) => {
                 // Close context menu
                 self.context_menu = None;
@@ -5582,6 +5662,11 @@ impl Tab {
                     continue;
                 }
 
+                if !item.allow_generate_thumbnail(&self.thumb_config.thumbnail_mode) {
+                    // Skip generating thumbnail if not permitted for thumbnail mode
+                    continue;
+                }
+
                 match item.rect_opt.get() {
                     Some(rect) => {
                         if !rect.intersects(&visible_rect) {